Louver mechanism for attic ventilation



Oct. 27, 1942. E. A. MADER LOUVER MECHANISM FOR ATTIC VENTILATION 3 Sheets-Sheet 1 Filed May 20, 1940 Snnentor Emil A.Mac1'zr Oct. '27, 1942- E. A. MADER 2, 3

LOUVER MECHANISM FOR ATTIC VENTILATION Filed May 20, 1940 s Sheets-Sheet 2 3nventor Emil A. Nader k attorney a Oct. -27, E, A, LO UVER MECHANISM FQR ATTiC VENTILATION Filed May 20-, 1940 3 Sheets-Sheet 3 A H v All mil Mad- Patented Oct. 27,- 1942 Emil A. Mader,.;Detroit, Mich., ass'ignor of onehalf to John Spargo, Detroit, Mich.

Applicaticn May 20, 1940, Serial No. 336,179

17 Claims. (61. 98-116) This invention relates to louver mechanisms and particularly to louver mechanismsfor updraft control. I

Pivotal louvers have heretofore beenfernployed tocontrola fan-induced upfiow of air,and the weight of such louvers has served to close them upon stopping the fan, and a spring 'hasbeen associated with the louvers to facilitate, their opening, on starting the fan.

An object of the invention is to facilitate the air-induced upward opening of va setof pivotal louvers or the likeby a mechanism disposed en- "tirely above the louvers and concealed by them,

when closed, eliminating need of any grille underlying the louvers.

Another object is to extend a coiled spring above a set of pivo'tal louvers controlling an uplllow of air, and substantially transverse to the air flow, and to connectsaidspring to the louvers.

for facilitating their opening responsive to upward air pressure, the connection being such as to derive a maximum effect from the spring when the louvers are in their closedpos'itions, in which their weight induced resistance to opening is also am'aximum. r

A further object is to provide a mechanism facilitating an air-induced upvva'rd opening of louvers and so retarding their closing travel when draft is cut off, that they will close quietly.

A further object is to provide means serving as a fire precaution for automatically establishing the closed positions of a set of upwardly opening louvers, in event the air rising past said louvers becomes unduly hot. I

A further object is to provide a set of pivotal louvers controlling an upflowof air and having "a provision for reducing the weight-induced resistance of the louvers to opening travel, such provision including a fusible element to permit the louvers to close of their own weight in case of fire, and said provision being such as to positively lock the louvers in closed position upon the yielding of such element.

A further object is to facilitate'jan air-induced louvers closed.

Fig. 2 is a vertical sectional view of the same taken upon the line 2 -2 of Fig. 1. r H Fig. 3 is a cross sectional view of the louver mechanism taken upon the line 33 of Fig. 2.

Fig. 4 is a vertical sectional view similar to Fig. 2 but showing a modified mechanism to facilitate opening of the louvers, the latter being shown in open position. i

Fig. 5 is a perspective View of the same show ing the louvers as normally closed.

Fig. 6 is a fragmentary sectional elevational view of the same, showing the louvers locked in closed position.

Fig. 7 is a top plan view of the invention, in a further modified form.

Fig. 8 is a longitudinal sectional elevation of the further modification, taken on the line B -8 of Fig. 7, showing the louvers open. 7

Fig. 9 is a similar view of such modification, showing'the louvers closed.

Describing first the preferred construction shown in Figs. 1, 2, and 3, the reference character l designates a frame constructed preferably of angle bars and forming a rectangular opening for the upflow of air, such flow being controlled by a set of horizontally elongated sheet metal louvers 2 pivoted in said frame so to occupy substantially the same horizontal plane in their closed positions. Said louvers are mounted on cylindrical pivot rods 3 which are terminally journaled in opposite sides of saidframe, the connection of the louvers to such rods being es tablished preferably by upwardly bending the pivotalmargins of the louvers as indicated at 4 and securing the rods within the angles thus formed. The preferred connection between the louvers rods is established by a suitable number of spot welds. The free edge portion of each louver (excepting an end louver of the set) overlaps the pivotal margin of an adjoining louver, when the louvers are closed, this relation being permitted by arching the free edge portions as indicated at 5. For sealing the clearance gap between the frame and louvers a sheet metal flange 5 projects from the frame into the opening thereof beneath and in close proximity to the louvers, said flange being coextensive with the frame.

l The several louver's are connected for actuation in unison by a link bar '1 pivotally connecting angle brackets 8 carried one upon the arched free edge portion 5 of each louver, said brackets projecting upwardly and being inclined away from the pivotal edges of the corresponding louvers best appears in Fig. 2, link bar being disposed preferably midway between the louver ends. Entendingacross the frame i above the louvers is a crank-forming roclgshaft 9 its aids parallel tothe louver pivots, the extremities of said shaft bein journal-ed in a pairoi brackets it opp'm sitely upwardly projecting from the frame. The

cranli formed by said shaft i of inverted V-shape, its altitude being such as to substantially clear.

the link bar 1 when the louvers are in open position. Said shaft is connected to the link bar by a swinging link ll engaging a plate l2 fixed on said shaft at its apex, the shaft and said link extending upwardly toward each other and being preferably inclined toward each other in the closed position of the louvers. The plate 12 projects above the apex of the shaft 9 for engagement by a fusible link l3 connecting said plate to a coiled spring l4 extending to the upper end of a post l5 upstanding from on end of the frame I. Preferably a hooked bolt I6 is secured by an adjusting nut l'l upon said post for engagement by the spring, whereby the tension of the latter may be regulated. Thi tension is such as to very largely counteract the weight of the louvers so that a quite moderate air pressure upwardly applied to the louvers suffices to open same and they will gradually return to their closed positions upon discontinuance of such pressure. Because of the gradual nature of their closing movement such movement will be noiselessly effected.

It is a vital feature of the described mechanism that th rockshaft 9 permits the spring to act upon the louvers, when closed, with suficient leverage to exercise the desired counterbalance effect on the latter. As the louvers open, swinging of the shaft 9 increases the leverage afforded th spring, but the lifting effect is not increased and is, in fact, gradually diminished due to the power loss accompanying contraction of the spring.

In the modified construction shown in Figs. 4 and 5, the pivotal mounting of louvers 2a in a frame la and their interconnection by a link bar la conforms to previous description. For largely counterbalancing the weight of the louvers, an arched rod l8, bridged across said frame, is mounted in sockets I9 welded or otherwise secured to opposite side bars of the frame. Pivoted on the arch l8 at its center, is a downwardly projecting link forming a toggle in conjunction with a relatively short link 2| pivoted on and upwardly projecting from the link bar la. The link 20 has a short longitudinal slot 22 to receive the rod l3, which slot permits the two link to be alternatively aligned or to form an obtuse angle, when the louvers are closed. Connected to the lower portion of the link 20 by a fusible link |3a is a coiled spring 23, which extends to a post I511 mounted on one end of the frame Ia and is connected to such post by a hooked bolt lea adjustable by a nut Hot, for regulating the spring tension. From the upper end of the link 20 an arm 2 projects substantially in the direction of the spring 23, and a weight 25, held selectively adjusted by a set screw 26, opposes the spring 23 and tends to establish the aligned position of the links 20 and 2|. A lug 21 on the lower end of the link 2!] is adapted to engage an edge of the link 2! to prevent the toggl breaking in the wrong direction.

In normal functioning of the described mechanism, the links 29 and 2| form an obtuse angle when the louvers are closed, the slot 22 of the upper link permitting it to thus swing out of alignment with th lower link. Hence, there is no locking of the louvers in closed position, and they will respond to a predetermined upward application of air pressure, reducing the angle formed by th toggle links. The force exerted on the toggle by the spring 23 predetermines the air pressure requisite to open the louvers. Leverage under which the spring acts decreases as the 2,2& vases louvers progressively open, but the strength of the spring is adequate to impose the desired opening travel on the louvers, particularly since weight resistance of the louvers to air pressure decreases in proportion to opening travel of the louvers.

In case the link 13a fuses due to abnormal heat, the louvers swing shut, due to their own weight, and the weight 25 shifts the links 20 :and H into alignment, positively locking the ilouvers in closed position.

Describing now the modification shown in Figs. "I, 8, and 9, the frame lb, pivotal louvers 2b with arched free edge portions 519, link bar lb, and brackets 81) all correspond to previous description. Mounted on one end of the frame lb is a post 28, having pivoted on its mid portion an arm 29 projecting above and transversely to the louvers and comprising a pair of spaced bars. From a hook 30 fixed on the fre end of said arm, a coiled spring 3| extend to the upper end of said post, a fusible link [31) being interposed between the spring and hook. J ournaled within the arm 29 and adjacent to its free end, is a :sheave 32 over which a cable Or equivalent element 33, extends downwardly for connection to the link bar 1b and lengthwise of said arm to engage a relatively light coiled spring 34 extending from a hooked adjusting bolt I61) transversely mounted on the post. A wing-nut l'lb engaging said bolt bears against the post, providing for regulation of the tension of th spring 34. The outer end of the arm 29 comprises a short downward projection 35, the purpose of which will be presently explained.

In use of the last-described mechanism, the pull exerted jointly by the springs 3i and 34 is slightly less than the aggregate force exerted by the weight of the louvers. Thus a very moderate air pressure suflices to open the louvers, and their closing movement, following discontinuanc of such pressure, will be gradual and substantially noiseless. If either of the described springs were used alone its tension could not be so regulated as to assure the desired easy opening of the louvers while still allowing them to close of their own weight. The two springs jointly, however, serve the purpose perfectly when th lighter one is properly adjusted.

If the link i379 fuses, by reason of its subjection to undue heat, the louvers close due to their own weight and the arm 29, for a like reason, swings down as shown in dash lines, Fig. 9, and seats the projection 35 on the closed louvers. The location on the arm of this projection is so selected that it will seat on one of the louvers in close proximity to the arched edge 51) of such louver, coacting with such edge to positively secure the louvers against opening.

The invention, in each of its described modifications, permits the louvers, when closed, to occupy a substantially flush relation with the bottom face of the ceiling in which the louver-controlled opening is formed. Thus the installation as viewed from beneath, does not materially detract from the appearance of a ceiling, and there is no need of any grille or the like to conceal the installation. The invention in its various forms is adequately safeguarded in case of fire, by a temperature-induced automatic closing of the louvers. The spring adjustment employed in each construction permits the counterbalancing force to be accurately regulated to suit the air pressure induced by any particular fan.

What I claim is: 1. A louver mechanism comprising a frame formed with an opening for air upflow, a set of louvers controlling said opening, means pivoting the louvers to swing about parallel axes, a link bar extending above the louvers and interconnecting them for actuation in unison, a coiled spring extending above the louvers and substantially transversely to their pivotal axes, an anchorage for one end of said spring disposed substantially aboveone end of said frame, a connection from the other end of said spring to said link bar for subiectingthe louvers to the spring to facilitate their opening, and a support for said connection mounted on the frame and applying the pull of the spring to the closed louvers in a substantially upward direction.

2. In a louver mechanism as set forth in claim 1, a fusible link through which one end of said spring is anchored.

3. In a louver mechanism as set forth in claim 1, a post upstanding from one end of said frame and forming said anchorage.

4'. A louver mechanism comprising a frame formed with an opening for air upflow, a set of louvers controlling said opening, means pivoting the louvers to swing about parallel axes, a link bar extending above the louvers interconnecting them for actuationin unison, a shaft journaled about an axis parallel to thepivotal axes of the louvers and provided with a crank disposed above at least one of the'louvers, a spring acting on the crank shaft tending to establish its crank in an upwardly projecting position, and a connection from the crank to said link bar for upwardly applying the stress of the spring to the louvers.

5. A louver mechanism as set forth in claim 4, said spring being coiled and elongated in approximate parallelism with the link bar and having one of its extremities attached to the crank.

6. A louver mechanism as set forth in claim 4, said crank shaft being engageable by one of said louvers to limit opening travel of the louvers.

7. A louver mechanism as set forth in claim 4, the crank shaft being journaled on said frame at opposite sides thereof and extending across said opening, with its axis of rotation in proximity to the pivotal axis of one of the louvers.

8. A louver mechanism comprising a frame formed with an opening for air upflow, a set of louvers controlling said opening, means pivoting the louvers to swing about parallel axes, a link bar extending above the louvers interconnecting them for actuation in unison, a spring acting upon the louvers and largely counteracting their weight, and a connection transmitting the effort of the spring to the louvers, said connection including a fusible element, and further including means for locking the louvers in closed position on fusing of said element.

9. A louver mechanism comprising a set of pivoted louvers, a spring biasing the louvers toward their open position and normally overcome by the weight of the louvers, fusible anchorage means for one end of the spring, a toggle linkage transmitting the effort of said spring to the louvers, said linkage having a position of substantial alignment of its links in which it positively resists opening of the louvers, and means normally overcome by said spring biasing the linkage to said position.

10. A louver mechanism as set forth in claim 9, the last-named means being a weight.

11. A louver mechanism comprising a frame formed with an opening for air upfiow, a set of upwardly opening louvers controlling said opening, means pivoting the louvers to swing about parallel axes, a link bar interconnecting the louvers for actuation in unison, a support upwardly spaced from the link bar, a pair of pivotally connected toggle links one extending downwardly from said support and the other extending upwardly from said link bar, and a spring biasing the louvers toward their open position and taking effect through said toggle links.

12. A louver mechanism as set forth in claim 11, said spring being coiled and extending substantially transversely to the pivotal axes of the louvers and taking effect on one of the toggle links adjacent to the pivotal connection between said links.

13. A louver mechanism as set forthin claim 11, said support being bridged across the opening of said frame.

14. A louver. mechanism comprising a frame formed with an opening'for air upfiow, a set of upwardly opening louvers. controlling said opening means pivoting the louvers to swing about parallel axes, a link bar interconnecting the louvers for actuation in unison, means for continuously imposing on the louvers a force biasing them toward their open position, said means including a'toggle linkage effective on said link bar, and further including an element responsive to abnormal heat to relieve the toggle linkage of said force and permit closing of the louvers, and means effective on said linkage to align the links thereof in a louver locking position, when the linkage is relieved of said force.

15. The combination with a pivotal closure gravity-biased to its closed position, of two springs jointly effective on said closure to largely counteract its gravity bias, one of said springs being relatively weak, a pivotal arm urged by the stronger spring in the direction of opening of said closure, the weaker spring being tensioned lengthwise of said arm, an elongated flexible connection between the weaker spring and closure, and a sheave journaled on said arm and guiding said flexible connection and adapting both springs to act on the closure in substantially its direction of opening.

16. The combination with a pivotal closure gravity-biased to its closed position, of two springs jointly eifective on said closure to largely counteract its gravity bias, one of said springs being relatively strong, a fusible link through which the effort of the last-mentioned spring is transmitted, and means for locking the closure in closed position normally rendered ineffective by said relatively strong spring.

17. The combination with a frame and an upwardly opening closure pivotally mounted in said frame, a member rigidly upwardly projecting from said frame at one end thereof, a substantially rigid arm pivoted upon said member for up and down movement and projecting above and normally upwardly spaced from the closure, a connection from said member to said arm including a spring urging the arm upwardly and further including a fusible element, a connection from said arm to the closure for transmitting the spring effort to the closure, the arm being gravity-urged toward the closure when relieved of the spring effort, and means carried by the arm adjacent to itsfree end acting to lock the closure in closed position when the arm is relieved of the spring effort.

EMIL A. MADER. 

